London Wasps wing Christian Wade is an injury concern for England after limping off against London Irish last Saturday.
The 22-year-old is due for a scan on Monday to determine the damage to his ankle, according to Wasps boss Dai Young and the club's Twitter account.
Wade has been talked up to start in the Six Nations following injuries to Marland Yarde and Ben Foden.
"Christian has gone over on his ankle but it's too soon to know what he's done yet," Young told the BBC.
"It's swollen but he will go and have a scan on it."
The news is the latest blow for England in the back-three, after Yarde was expected to miss the start of the Six Nations due to a hip injury.
Foden meanwhile has been ruled out until the end of February after injuring his knee playing for Northampton against Newcastle.
"Ben is a quick healer so he thinks he can get back before then but you cannot rush these things," Mallinder told the Northampton Chronicle.
"He's in a positive frame of mind. It could have been worse, it could have been better.
"I think it will be around the 12-week mark that Ben will be out for. It's very unfortunate for him. He's very confident he can get back before then, he's always positive, which is good, so we'll have to see how that goes."